The thing is that those teams don't have a particularly high ceiling, they just get by.
I wanna see them vs Bills, Chiefs, Ravens and the Eagles, teams with a high ceiling. And who odds-wise are together with the Lions on a completely different level than the 2nd tier in Houston, Vikings, Steelers etc.
It has happened before that people with easy wins have big problems when they aren't prepared for adversity. When they haven't played against a team with a crazy running game all season, when they haven't played against a defense that easily keeps most teams under 20 etc.
I'm not saying that this is the case, but it my only worry regarding their title chances. It's not science.